Computers may be used to search for particular data objects using search queries. Data objects may be information stored in a memory element of a computer, such as text strings, numbers, or metadata associated with objects such as pictures, videos, etc. A data object may have one or more searchable characteristics associated with the data objects. A search query may be used to search for a particular type of data object or for data objects having one or more associated characteristics. Search queries may be entered using any suitable method, such as text strings, hypertext, or a search query language such as SQL. Structured queries may be used to perform search queries that have multiple constraints on the type of data object or particular data-object characteristics searched for.